ELECTRONIC AND GEOMETRICAL EFFECTS ON THE MAGNETISM OF SMALL RU-N CLUSTERS

Size-dependent, magnetic and structural properties of small Ru-N clust ers are calculated using a tight-binding Hubbard Hamiltonian in the un restricted Hartree-Fock approximation. The calculated average magnetic moment shows very strong oscillations as a function of the cluster si ze, which is in contrast with the almost independent behavior previous ly found in the iron-group clusters, Small cohesive energy differences are found between isomers while on the contrary, the magnetic moments differ considerably. Our results are in agreement with the existing e xperimental measurements, (C) 1998 Elsevier Science B.V. All rights re served.